Electron spin resonance studies. Part XXXI. The generation, and some reactions, of the radicals SO3–·, S2O3–·, S–·, and SH in aqueous solution

Abstract

Evidence has been adduced by e.s.r. spectroscopy for the formation of the sulphite radical anion, SO₃^–·[by the oxidation of sulphite ion with the hydroxyl or amino-radical, the sulphate radical anion, or cerium(IV) ion], of the thiosulphate radical anion, S₂O₃^–·(from thiosulphate ion and the hydroxyl radical), and of the sulphide radical ion, S^–·(pH 9) or the mercapto radical, ·SH (pH 2)(from sulphide ion and the hydroxyl or amino-radical). The radical anions are efficiently captured by nitroalkane aci-anions. The sulphite radical anion shows marked selectivity in its reactions with olefinic carbon. The splitting constants of the radicals formed by addition of the species S^–· and ·SH to two olefinic compounds suggest that there is an interaction between the sulphur substituent and the tervalent carbon atom.